Project Summary In 2013, 1,258 children (1.71 per 100,000) died by gunshot and an additional 6,103 (8.29 per 100,000) had a nonfatal gunshot injury. Additionally, in 2010 youth firearm-related fatal and nonfatal injuries resulted in an estimated $2.6 billion in combined medical and work loss costs. Acknowledging these striking numbers, a wide range of policy interventions have been developed to help reduce such violent crimes, with mixed-results. Still, we know surprisingly little about children's exposure to guns and the implications of that exposure on risk for violence, injury, and death. This is despite policy statements and recommendations from groups like the American Academy of Pediatrics and the USDHHS Healthy People 2020 emphasizing the importance of finding strategies for reducing the risks associated with children's firearm access and exposure. Past research on youth firearm exposure has focused on only a limited range of exposures, such as firearm carrying on school property, yet youth firearm exposure is not limited to schools or to carrying. Indeed, there are no instruments that cover the full spectrum of childhood firearm exposure. Such a lack of youth-focused surveys limits the ability to assess the developmental impact of exposure and identify the most important targets for policy and programs that aim to reduce firearm-related fatal and non-fatal injury among children. This gap is notable given there are considerations unique to childhood, such as inappropriate or illegal access to firearms, exposure to gun violence involving caregivers which may be particularly traumatic, and the developmental impact of exposure to effective gun safety practices. In addition to different considerations regarding exposure, there are also important methodological adaptations that are necessary for youth, including more careful attention to reading level and avoiding use of legalistic terms. The present research will allow for the collection and analysis of firearm exposure information relevant to the entire span of childhood and adolescence. Specifically, we aim to: 1) Develop the first comprehensive, developmentally focused Youth Firearm Risk and Safety Tool (Youth-FiRST); and 2) Pilot test the Youth-FiRST within two communities at high-risk for gun violence ? rural Appalachia, TN and urban Philadelphia, PA. The Youth-FiRST items will be developed through a mixed-methods approach, including focus groups with teenagers and parents, review by violence experts, and cognitive interviews with children (ages 10-15) for comprehension. Pilot community data from 300 youth, ages 10-17, and 300 caregivers of children, ages 2-9 (proxy interviews), will be used to establish psychometrics of the Youth-FiRST including internal consistency, factor structure, and construct validity utilizing techniques such as Item Response Theory (IRT) and Differential Item Functioning (DIF). Findings will help the field address youth exposure to firearms and associated violence exposure using a more integrative approach, directly facilitating our ultimate outcome objectives which are to increase appreciation of the true burden of firearm exposure and firearm violence on the most vulnerable segment of the population.